Clay contacting process



De 13, 1955 R. H. DUDLEY ETAL CLAY CONTACTING PROCESS` Filed NOV. l5 1951 GOA/@130095 Cmborrzeg .Quik 01 Roert Inman United States Patent() CLAY CONTACTING PROCESS Richard H. Dudley, Cranford, and Robert L. Weeks,

Union, N. J., assignors to Esso Research and Engineering Company, a corporation of Delaware Application November 13, 1951, Serial No. 256,048

2 Claims. (Cl. 196-147) The present invention is concerned with the rening of petroleum oils utilizing clay. The invention is more particularly concerned with an integrated refining operation wherein a relatively low boiling distillate and a heavy residual oil is contacted with clay in a manner to improve their quality with a minimum loss of clay and oil. In accordance with the present invention, a low boiling distillate is irst contacted with clay and the clay thereafter utilized in conjunction with fresh clay to treat a residual stock in order to secure high quality products, and a minimum loss of clay and oil.

It is well known in the art to refine mineral oils such as petroleum oils, lubricating oils and the like by contacting these oils at various temperatures with clays such as activated bentonite clay of the montmorillonite class having the general structure (Mg.Ca.)O.Al2O3.5 SiO2.n H2O in which the crystals are arranged in silicon-oxygen sheets. Best decolorizing efficiency is secured when these clays are acid treated to a SiOz to A1203 ratio of four. A suitable clay of this class is Super Filtrol.

In these operations it is desirable to use a minimum amount of clay in order to secure the desired improvement and also to carry out the clay contacting process in a manner that a minimum amount of oil is lost on the clay. It has now been discovered that unexpected desirable results are secured when treating petroleum oils boiling above about 650 F. provided the oil is separated into a distillate fraction, which distillate fraction is contacted with clay and into a residual fraction, which fraction is contacted with the spent clay from the distillate treating operation preferably in combination with a fresh clay treat.

The present invention may be more fully appreciated by the drawing illustrating an embodiment of the same. Referring specifically to the drawing, a lubricating petroleum oil boiling in the range above about 650 F. is introduced into distillation zone 1 by means of feed line 2. Temperature and pressure conditions in zone 1 are adjusted to remove overhead by means of line 3 a distillate fraction boiling in the range from about 650 to 950 F. This distillate fraction may be dewaxed in dewaxing zone 4, Withdrawn from dewaxing zone 4 by means of line 5 and solvent extracted in zone 6 in order to separate the more aromatic type constituents from the more paraflinic type constituents. The dewaxed and solvent extracted oil is then introduced into a clay treating zone 7 by means of line 8. Under certain operations it may be desirable to by-pass either the dewaxing or the solvent treating operation or both by means of lines 9, 10 and 11. It is to be understood that the oil may be acid treated with an acid such as sulfuric acid and neutralized.

It is to be understood that distillation zone 1, dewaxing zone 4 and solvent extraction zone 6 may comprise any suitable number and arrangement of stages. Also, any suitable dewaxing operation may be conducted utilizing dewaxing solvents, oil solvents and various types of apparatus for the segregation of the waxy constituents from the oil such as lter drums, plate and frame presses,

y 2,726,997 Patented Dec. 13, 1955 ICC centrifuges and the like. The solvent extraction operation likewise may comprise any suitable type of procedure utilizing aromatic solvents such as phenol and paranic types of solvents such as propane and the like.

A residuum fraction is withdrawn from distillation zone 1 by means of line 12 deasphalted in zone 30, withdrawn by means of line 31 and passed through a dewaxing zone 13 and a solvent extraction zone 14. This fraction, under certain conditions, may by-pass either the dewaxing operation or the solvent extraction operation by means of lines 15, 16 and 17.

In accordance with the present operation, the distillate oil is introduced into clay treating zone 7 by means of line 8 and contacted in said zone with fresh clay introduced by means of line 18. rIhe treated oil is withdrawn from clay treating zone 7 by means of line 19 and further handled or refined as desired. In accordance with the present invention, at least a portion of the spent clay from zone 7 is introduced into spent clay treating zone 20 by means of line 21. Spent clay from zone 7 may be withdrawn from the system by means of line 22 while spent clay from zone 20 with be withdrawn from the system by means of line 23.

'Ihe residual fraction, clay treated in zone 20, is withdrawn from zone 20 by means of line 24 and passed to a fresh clay treating zone 25 wherein the same is contacted with fresh clay. The treated oil is withdrawn from zone 25 by means of line 26 and further refined or handled as desired.

The invention is broadly concerned with an integrated operation for clay treating particular fractions of a mineral oil. The invention is particularly concerned with the treatment of a distillate fraction with clay followed by the utilization of at least a portion of the spent clay for the treatment of a residual fraction. It is preferred that the distillate fraction and the residual fraction be secured from the same feed and segregated by a distillation operation, but it is to be understood that the distillate fraction and the residual fraction may be secured from different rening operations.

A preferred distillate fraction is one which has been distilled and which boils above about 650 F., preferably in the range from about 700 F. to 950 F. The gravity of the distillate fraction should be in the range from about 27 to 33 A. P. I. The residual fraction is one which boils in the range above about 950 F., preferably one which boils above 1000 F. The gravity of the resildual fraction is preferably in the range from about 22 to 26 A. P. I.

It is also preferred that the distillate fraction be contacted with clay at a temperature in the range from about 30G-500 F., preferably in the range from about 350- 450 F. The temperature for contacting the residual fraction should be somewhat higher, preferably about F. above that used for the contacting of the distillate fraction.

The amount of clay employed in treating the distillate fraction should be in the range from about 0.1 to 0.5 lbs. per gallon while the amount of clay employed for the treatment of the residual fraction should be in the range from about .3 to 2 lbs. per gallon of spent clay and from about .3 to 1.5 lbs. of fresh clay per gallon of oil being treated. As pointed out, the preferred mode of operation is to first contact the residual fraction with spent clay from the clay contacting ofthe disillate fraction followed by the contacting of the residual oil after its removal from the spent clay contacting zone with a relatively small amount of fresh clay.

It is to be understood, however, that under certain conditions it may be sutlicient to Contact the residual fraction with a mixture of fresh and spent clay secured from the clay treatment of the distillate fraction.

3 The process of the present invention will be more readily understood by the following examples illustrating the same:

This oil was treated with *0.72` lb. per gallon of fresh Super FiltrolV clay at a temperature of 400 F. The color Y of thertreated oil was raised Vto 16% Tag Robinson.

Y This Voil in Operation 1 was treated with 11/2 lbs. per gallon of fresh Super Filtrol.

In a second operation, the oil was contacted with 11/2 lbs. of spent clay secured from the process described in Example l. Y

In a third operation the oil removed from Operation 2 was contacted with 0.5 lb. per gallon of fresh clay.

In a fourth operation the residual oil was contacted with a'mixture of 11/2 pounds per gallon of spent clay secured from the operation described in Example 1 and with 0.5 lb. per gallon of fresh clay.

The'results of these operations are as follows:

From the above, it is apparent that when utilizing only the fresh clay (Example l), theV oil loss of 20% is excessive. When employing 'spent clay, although the oil loss was considerably reduced (from 20% to 3.5 %)the Vcolor of 3A was not satisfactory.

However, when utilizing ,a second stage for the contacting of this oil employing 0.5% of fresh clay, the color increased to 21A; whereas the total oil loss equaled only 11% (3.5-}-7.5%).v This is about half the loss Vincurred in Operation 1. It is evident that Operation 4 is far superior to Operation 1 but isV not as' satisfactory as twostage operation, as illustrated by Operations 2 and 3.

What is claimed is: Y

l. Improved process for the production of high quality petroleum oil fractions from a feed oil boiling above aboutV 650 F. which comprises distilling said feed oil to secure a distillate fraction boiling in the range from about 650 to 950 F. and having a gravity in the range from about 27 to 33 A. P. 1. and into av residual fraction having an initial boiling point above about 1000. F. anda gravityl in the range from about 22-26 A. P. I., contacting said distillate fraction with fresh clay ink an initial clay contacting zone, removing spent clay from .said initial zone and contacting said residual oil in a secondary zone with said spent clay, removing saidresidual oil from said secondary `clay treating zone and contacting the same in a tertiary treating zone with fresh clay. y

2. Process as defined by claim 1 wherein the amount of fresh clay employed to contact saiddistillate fraction is about 0.2 lb. per gallon, and, wherein said residual oil is contacted in said secondary zone with about 1.5 lbs. per gallonY of said Spent clay, and wherein said residual oil is contacted in said tertiary treating zone with about 0.5 lb. of fresh clay per gallon.

References -Cited in the iile of this patent UNITED STATES PATENTS 2,273,104 Heilman Feb.V 17, 1942 2,340,939 Davis et al. Feb. 8, 1944 2,351,445 Morgan June 13, 1944 2,402,804 Chechot June 25, 1946 

1. IMPROVED PROCESS FOR THE PRODUCTION OF HIGH QUALITY PETROLEUM OIL FRACTIONS FROM A FEED OIL BOILING HAVING ABOUT 650* F. WHICH COMPRISES DISTILLING SAID FEED OIL TO SECURE A DISTILLATE FRACTION BOILING IN THE RANGE FROM ABOUT 650 TO 950* F. AND HAVING A GRACITY IN THE RANGE FROM ABOUT 27* TO 33* A. P. I. AND INTO A RESIDUAL FRACTION HAVING AN INITIAL BOILING POINT ABOVE ABOUT 1000* F. AND A GRAVITY IN THE RANGE FROM ABOIT 22-26* A. P. I., CONTACTING SAID ING ZONE, REMOVING SPENT CLAY FROM SAID INITIAL ZONE AND CONTACTING SAID RESIDUAL OIL IN A SECONDARY ZONE WITH SAID SPENT CLAY, REMOVING SAID RESIDUAL OIL FROM SAID SECONDARY CLAY TREATING ZONE AND CONTACTING THE SAME IN A TERTIARY TREATING ZONE WITH FRESH CLAY. 